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Specific Defense Against Disease The last type of defense against invading organisms is the specific line of defense. This defense by your body attacks specific pathogens and in the process produces antibodies that in the future can attack that specific pathogen if it occurs again.

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Third Line of Defense Immune Response: consists of an army of cells that combat specific pathogens Antigen: a substance that triggers an immune response Antibody: a ‘Y-shaped molecule that is produced by plasma cells when exposed to an antigen.

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Non-functioning immune response A person’s immune response is not functioning well if it is unable to fight pathogens. This is because their body cannot produce the specific antibody for that pathogen. AIDS is just such a disease because a patient’s body inability to defend itself against invading organisms.

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Antibodies and Antigens An antibody is produced by your body in response to a specific antigen. An antigen is a foreign substance which causes the body to produce a specific antibody.

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Antibodies attacking an antigen ‘Y’ shaped antibody

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Antibodies Antibodies are substances formed by the human body in response to foreign proteins entering the body.

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Resistance to Disease Immunity – resistance to a particular disease. Vaccination – a medical procedure used to produce immunity. Vaccine – a solution of dead or modified pathogens that can no longer cause disease.

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Vaccines and Infection Vaccines are effective in preventing disease because they are dead or modified pathogens with antibodies directed against a specific pathogen.